JP2017189213A - Reinforcing member and catheter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcing member having an excellent push-in property, torque transmission property, followability, and kink resistance, and a catheter including the reinforcing member.SOLUTION: A reinforcing member 2 extends along a drawing direction from a proximal end to a distal end, and reinforces a catheter 1. The reinforcing member 2 includes: a coiled part 3 as a tubular member formed by winding a wire strand into a coil shape, and having a lumen extending along the drawing direction from the distal end to the proximal end; a netted part 4 as a tubular member formed by knitting the wire strand into a net shape, and having a lumen extending along the drawing direction from the proximal end to the distal end; and a connection part for connecting a distal-side end of the coiled part 3 and a distal-side end of the netted part 4 and communicating the respective lumens with each other.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a reinforcing member for reinforcing a catheter and a catheter including the reinforcing member.

  Characteristics required for a catheter inserted into a blood vessel include pushability, torque transmission, followability, and kink resistance. The pushability is necessary to appropriately transmit the force in the extending direction applied to the proximal end side of the catheter to the distal end side when the catheter is moved forward to the target site in the blood vessel. Torque transmission is necessary to properly transmit the rotational force applied to the proximal end side of the catheter to the distal end side. The followability is necessary to smoothly advance the catheter in the bent blood vessel. The kink resistance is necessary to prevent the catheter from being bent at the bent portion of the blood vessel and collapsing the lumen.

  Various proposals have been made to meet the above characteristics in catheters. For example, Patent Document 1 proposes a medical device having a hollow body shaft (hereinafter also referred to as “reinforcing member”) in which a wire is wound in a coil shape. Patent Document 2 proposes a balloon catheter in which a reinforcing member made of a metal wire mesh is fixed to an inner tube.

JP 2005-296078 A Japanese Patent Laid-Open No. 10-57495

  In the case of a catheter having a coil-shaped reinforcing member as in Patent Document 1, the pushability and torque transmission may not satisfy the required level. On the other hand, in the case of a catheter having a mesh-like reinforcing member as in Patent Document 2, the followability and kink resistance may not satisfy the required level. For this reason, realization of the catheter excellent in all the characteristics is desired.

  An object of the present invention is to provide a reinforcing member excellent in pushability, torque transmission property, followability, and kink resistance, and a catheter having the reinforcing member.

  The reinforcing member according to the first aspect of the present invention is a reinforcing member that extends from the proximal end to the distal end along the extending direction and reinforces the catheter, and is a tubular member in which a strand is wound in a coil shape. A coil-shaped portion having a lumen extending from the distal end to the base end side along the extending direction, and a tubular member in which strands are knitted in a net shape, the lumen extending along the extending direction A coiled proximal end that is a proximal end of the coiled portion; and a meshed proximal end that is the proximal end of the coiled portion. Each of the lumens communicates with each other by joining a mesh tip that is an end of the mesh portion on the tip side.

  In the reinforcing member, the net-like portion provided on the base end side in the extending direction is excellent in pushability and torque transmission. For this reason, since the reinforcing member can appropriately transmit the force in the extending direction applied to the proximal end side to the distal end side, the reinforcing member can appropriately move forward to the target site in the blood vessel. Further, the reinforcing member can appropriately transmit the rotational force applied to the proximal end side to the distal end side. On the other hand, the coiled portion provided on the distal end side in the extending direction is excellent in followability and kink resistance. For this reason, the reinforcing member can proceed smoothly along the blood vessel when the reinforcing member moves forward in the bent blood vessel to the target site. Further, the reinforcing member can be prevented from being bent at the bent portion near the target site of the blood vessel and collapsing the lumen. Furthermore, the coiled base end of the coiled part and the meshed tip of the meshed part are joined. For this reason, the reinforcing member can have both the pushability and torque transmission performance of the mesh portion and the followability and kink resistance of the coil portion. Therefore, the reinforcing member can realize excellent characteristics in pushability, torque transmission property, followability, and kink resistance.

  1st aspect WHEREIN: You may provide the junction part which joins the said coiled base end and the said mesh-shaped front end. In this case, the coiled proximal end and the meshed distal end can be firmly joined by the joining portion.

  1st aspect WHEREIN: The said junction part may have a fastening part which covers the said coiled base end and the said mesh-shaped front end from the radial direction outer side of each lumen | bore of the said coil-shaped part and the said mesh-shaped part. In this case, the reinforcing member can appropriately join the coiled portion and the mesh portion.

  In the first aspect, the material of the fastening portion may be a radiopaque member. In this case, the reinforcing member can use the joint as a radiopaque marker. Therefore, the user can confirm the joint part of a coil-shaped part and a net-like part by a junction part under X-ray fluoroscopy.

  1st aspect WHEREIN: The said coiled base end may be located in the said base end side in the said extending | stretching direction rather than the said net | network shaped front end. In this case, a part of each of the coiled portion and the mesh portion overlaps in the extending direction. For this reason, the reinforcing member can join the coiled portion and the net-like portion at portions overlapping each other.

  In the first aspect, a coil pitch of a coil distal end region including at least a coiled distal end that is an end on the distal end side of the coiled portion may gradually increase from the proximal end side toward the coiled distal end. The reinforcing member may be used by inserting a tip into a blood vessel having a large degree of bending. On the other hand, the reinforcing member can make the coil tip region of the coiled portion softer toward the tip. That is, since the followability at the tip is particularly excellent, the tip of the reinforcing member can be inserted even in a blood vessel having a large degree of bending.

  In the first aspect, the coil pitch of the coil proximal end region including at least the coiled proximal end of the coiled portion may gradually decrease from the distal end side toward the coiled proximal end. In the reinforcing member, the curvature when bent according to the application of external force changes according to the hardness. For this reason, the curvature also changes abruptly at a portion where the hardness changes abruptly in the stretching direction. In the reinforcing member, since it is preferable that the change in curvature when bent is small, the change in hardness in the extending direction of the reinforcing member is preferably small. Usually, the hardness of the coiled portion is often smaller than the hardness of the mesh portion. On the other hand, in the reinforcing member, the coil base end region of the coiled portion can be made harder as the coil base end is gradually decreased by gradually decreasing the coil pitch of the coil base end region from the tip side toward the coil base end. Thereby, the reinforcement member can make small the change of the hardness of the extending | stretching direction in the junction part which the coil-shaped part and the net-like part joined. Therefore, the curvature when the reinforcing member is bent can be made substantially constant.

  The catheter according to the second aspect of the present invention includes the reinforcing member according to the first aspect and a tubular member that covers the reinforcing member. According to the 2nd aspect, the catheter can implement | achieve the characteristic excellent in pushing property, torque transmission property, followable | trackability, and kink resistance with a reinforcement member.

  2nd aspect WHEREIN: The said tubular member has a diameter same area | region whose outer diameter is substantially the same over the said extending direction, The said diameter same area | region has a part from which the hardness differs in the said extending direction. Also good. In order for the catheter to move smoothly in the blood vessel, the outer diameter of the catheter is preferably uniform. In addition, in the catheter, the distal end portion, which is often inserted into a bent blood vessel, is preferably small in hardness, and the proximal end portion hardness to which force is applied when the catheter is pushed into the blood vessel from outside the body is directly applied. Is preferably larger. On the other hand, the catheter has a portion with different hardness in the same diameter region where the outer diameters are substantially the same. For this reason, while making the outer diameters substantially the same, the hardness on the distal end side can be made smaller and the hardness on the proximal end side can be made larger. Therefore, the catheter can realize characteristics excellent in followability at the distal end portion and pushability at the proximal end portion.

  2nd aspect WHEREIN: The said tubular member has the hardness same area | region where hardness is substantially the same over the said extending | stretching direction, and the part which the said coiled base end and the said mesh-shaped front end join is said hardness. It may be included in the same area. In the catheter, the curvature when bent according to the application of external force changes according to the hardness. For this reason, the curvature also changes abruptly at the portion where the hardness in the stretching direction changes abruptly. In the catheter, since it is preferable that the change in curvature when bent is small, the change in hardness in the stretching direction of the catheter is preferably small. On the other hand, in a catheter, the part which a coil-shaped part and a mesh-shaped part join in a reinforcement member is contained in the hardness same area | region where hardness is substantially the same in a tubular member. In this case, the difference in hardness between the coil-shaped portion and the mesh-shaped portion in the reinforcing member can be alleviated by the tubular member. Therefore, the catheter can reduce the change in the hardness in the extending direction at the portion where the coiled proximal end and the meshed distal end of the reinforcing member are joined, so that the curvature when the catheter is bent can be made substantially constant.

  2nd aspect WHEREIN: The said tubular member is a some area | region covering the said extending | stretching direction, Comprising: 3rd which was pinched | interposed between the 1st area | region, the 2nd area | region, and the said 1st area | region and the said 2nd area | region. The first region has a first hardness, the second region has a second hardness greater than the first hardness, and the third region has a hardness. However, you may change from the said 1st hardness to the said 2nd hardness toward the said 2nd area | region side from the said 1st area | region side. In this case, the catheter can be relatively increased in hardness by setting the distal end side as the first region and relatively increased in hardness by setting the proximal end side as the second region. Therefore, the catheter can realize characteristics excellent in followability at the distal end portion and pushability at the proximal end portion. Further, the change in the hardness of the catheter can be moderated by changing from the first hardness to the second hardness in the third region. Therefore, a change in curvature when the catheter is bent can be suppressed.

1 is a side view of a catheter 1. FIG. It is sectional drawing to which the part of the frame line W1 of FIG. 1 was expanded. It is sectional drawing to which the part of the frame line W2 of FIG. 1 was expanded. 4 is an enlarged side view of the vicinity of a frame line W2 in the reinforcing member 2. FIG. It is sectional drawing which looked at the AA line of FIG. 2 from the arrow direction. It is sectional drawing which looked at the BB line of FIG. 2 from the arrow direction. It is sectional drawing which looked at CC line of FIG. 1 from the arrow direction. It is sectional drawing which looked at the DD line | wire of FIG. 1 from the arrow direction. It is sectional drawing which looked at the EE line | wire of FIG. 1 from the arrow direction.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The catheter 1 is a microcatheter used for applications such as embolization. As shown in FIG. 1, the catheter 1 includes a reinforcing member 2 and a tubular member 5. Hereinafter, an end corresponding to one side of both ends of the catheter 1 is referred to as a “tip”. An end corresponding to the other side of both ends of the catheter 1 is referred to as a “base end”. A connector 9 for passing a wire or the like through the catheter 1 is connected to the proximal end of the catheter 1. A direction extending along the catheter 1 is referred to as a “stretching direction”. Of the radial direction based on the cross-sectional center of the catheter 1 on a plane orthogonal to the extending direction, the side close to the cross-sectional center of the catheter 1 is referred to as “inside”, and the side separated from the cross-sectional center of the catheter 1 is “ It is called “outside”.

<Reinforcing member 2>
The reinforcing member 2 is a tubular member having flexibility. The reinforcing member 2 has a function of reinforcing the strength of the catheter 1 in the extending direction. The length L2 of the reinforcing member 2 in the extending direction is approximately 1615 mm. The reinforcing member 2 extends from the proximal end to the distal end along the extending direction. The reinforcing member 2 includes a coiled portion 3, (see FIGS. 2, 3, and 4), a mesh portion 4 (see FIGS. 3 and 4), and a fastening portion 6 (see FIG. 2) and 7 (see FIG. 2). ), 8 (see FIGS. 3 and 4).

<Coil-shaped part 3>
As shown in FIG. 4, the coiled portion 3 is formed by winding a wire in a coil shape along the outer peripheral surface of the tubular inner layer portion 21. The diameter of the wire forming the coiled portion 3 is approximately 0.025 mm, and the material is SUS (stainless steel). As shown in FIGS. 5 to 9, the inner layer portion 21 has an inner diameter R2 of approximately 0.42 mm and a thickness of approximately 0.02 mm. The material of the inner layer portion 21 is PTFE (polytetrafluoroethylene). As shown in FIG. 2, the lumen 3 </ b> A of the coiled portion 3 is formed inside the inner layer portion 21. The inner side and the outer side in the radial direction of the lumen 3A coincide with the inner side and the outer side of the catheter 1, respectively. The inner diameter of the lumen 3A is substantially the same as the inner diameter R2 of the inner layer portion 21, and is approximately 0.42 mm. The lumen 3A extends from the distal end of the catheter 1 toward the proximal end side. As shown in FIG. 1, the length L3 of the coiled portion 3 in the extending direction is approximately 300 mm.

  As shown in FIG. 2, the coil includes a distal end side end (hereinafter referred to as “coiled distal end 3 </ b> P”) of the coiled portion 3, and extends in the extending direction from the coiled distal end 3 </ b> P toward the proximal end side. The predetermined region of the shape portion 3 is referred to as a “coil tip region 31”. The length L31 (see FIG. 1) in the extending direction of the coil tip region 31 is approximately 150 mm. As shown in FIG. 3, the coiled portion 3 includes a proximal end (hereinafter referred to as “coiled proximal end 3 </ b> B”) and extends in the extending direction from the coiled proximal end 3 </ b> B toward the distal end. The predetermined area of the coiled portion 3 is referred to as a “coil proximal end area 32”. The length L32 (see FIG. 1) in the extending direction of the coil proximal end region 32 is approximately 150 mm. The position of the end portion on the proximal end side of the coil distal end region 31 coincides with the position of the end portion on the distal end side of the coil proximal end region 32.

  The coil pitch of the coil tip region 31 (see FIG. 2) gradually increases from approximately 0.1 mm toward the coiled tip 3P from the base end side. The coil pitch at the coiled tip 3P is approximately 3 mm. The coil pitch of the coil proximal end region 32 (see FIG. 3) gradually decreases from approximately 0.1 mm from the distal end side toward the coiled proximal end 3B. The coil pitch at the coiled base end 3B is approximately 0.05 m.

<Reticulated part 4>
As shown in FIG. 4, the mesh portion 4 is disposed on the proximal end side of the coiled portion 3. The mesh portion 4 is formed by braiding strands in a mesh shape along the outer peripheral surface of the inner layer portion 21. The diameter of the strands forming the mesh portion 4 is approximately 0.025 mm, and the material is SUS (stainless steel). The woven structure of the mesh portion 4 is a twill weave, and the pitch of the strands is approximately 1.2 mm. As shown in FIGS. 3 and 4, the end of the mesh portion 4 on the distal end side (hereinafter referred to as “mesh distal end 4 </ b> P”) is adjacent to the proximal end side of the coiled proximal end 3 </ b> B of the coiled portion 3.

  As shown in FIG. 3, the lumen 4 </ b> A of the mesh portion 4 is formed inside the inner layer portion 21. The inner side and the outer side in the radial direction of the lumen 4A coincide with the inner side and the outer side of the catheter 1, respectively. The inner diameter of the lumen 4A is substantially the same as the inner diameter R2 (see FIGS. 5 to 9) of the inner layer portion 21, and is approximately 0.42 mm. The lumen 4A extends from the proximal end of the catheter 1 toward the distal end side. As shown in FIG. 1, the length L4 of the mesh part 4 in the extending direction is approximately 1315 mm.

<Fastening parts 6, 7, 8>
As shown in FIG. 2, the fastening portion 6 is provided in a portion including the coiled tip 3 </ b> P in the coil tip region 31 of the coiled portion 3. The fastening part 6 is a cylindrical member. The center of the fastening portion 6 extends in the extending direction. The length L6 in the extending direction of the fastening portion 6 is approximately 0.6 mm. As shown in FIG. 6, the inner diameter of the fastening portion 6 is slightly larger than the inner diameter of the lumen 3 </ b> A of the coiled portion 3. The thickness of the fastening portion 6 is approximately 0.03 mm. The fastening part 6 covers the coiled part 3 from the outside. The fastening portion 6 is fixed to the coiled portion 3 by being caulked by applying pressure from the outside to the inside of the catheter 1.

  As shown in FIG. 2, the fastening portion 7 is provided at a position spaced from the proximal end side of the fastening portion 6 toward the proximal end side. The shape of the fastening portion 7 is the same as that of the fastening portion 6. The length L7 in the extending direction of the fastening portion 7 is approximately 0.6 mm. The center of the fastening portion 7 extends in the extending direction. As shown in FIG. 6, the fastening part 7 covers the coiled part 3 from the outside. The fastening portion 7 is fixed to the coiled portion 3 by being caulked by applying pressure from the outside to the inside of the catheter 1. As shown in FIG. 2, the length L67 in the extending direction between the end on the distal end side of the fastening portion 6 and the end on the proximal end side of the fastening portion 7 is approximately 30 mm.

  As shown in FIGS. 3 and 4, a fastening portion 8 is provided at a portion covering the coiled base end 3 </ b> B of the coiled portion 3 and the meshed tip 4 </ b> P of the meshed portion 4. The fastening portion 8 is a cylindrical member. The center of the fastening portion 8 extends in the extending direction. The length L8 in the extending direction of the fastening portion 8 is approximately 0.6 mm. The thickness of the fastening portion 8 is approximately 0.04 mm. The fastening part 8 covers the vicinity of the coiled base end 3B of the coiled part 3 and the vicinity of the meshed tip 4P of the meshed part 4 from the outside. The fastening portion 8 joins the coiled proximal end 3B of the coiled portion 3 and the meshed tip 4P of the meshed portion 4 by applying pressure from the outside to the inside of the catheter 1. Thus, the lumen 3A of the coiled portion 3 and the lumen 4A of the mesh portion 4 communicate with each other. The boundary portion between the coiled base end 3 </ b> B of the coiled portion 3 and the meshed tip 4 </ b> P of the meshed portion 4 is disposed at the approximate center of the fastening portion 8 in the extending direction.

  The material of the fastening portions 6, 7, 8 is a known radiopaque member that does not transmit radiation (for example, Pt (platinum)).

<Tubular member 5>
As shown in FIGS. 2 and 3, the tubular member 5 is a tubular member provided along the outer peripheral surface of the inner layer portion 21. The tubular member 5 covers the reinforcing member 2 from the outside over the entire region in the extending direction. The material of the tubular member 5 is a blend of nylon 12 and nylon elastomer. The lumen 5 </ b> A of the tubular member 5 is formed inside the inner layer portion 21. The inner side and the outer side in the radial direction of the lumen 5A coincide with the inner side and the outer side of the catheter 1, respectively. The inner diameter of the lumen 5A is substantially the same as the inner diameter R2 (see FIGS. 5 to 9) of the inner layer portion 21, and is approximately 0.42 mm. The lumen 5A extends from the distal end of the catheter 1 to the entire region of the proximal end. As shown in FIG. 1, the length L5 of the tubular member 5 in the extending direction is substantially the same as the length L2 of the reinforcing member 2 in the extending direction, and is approximately 1615 mm. As shown in FIG. 2, the end on the distal end side of the tubular member 5 (hereinafter referred to as “tubular distal end 5 </ b> P”) is disposed on the distal end side relative to the coiled distal end 3 </ b> P of the coiled portion 3 of the reinforcing member 2. The corner of the tubular tip 5P is curved.

  As shown in FIG. 1, the tubular member 5 can be divided into four regions according to the outer diameter. Hereinafter, the four regions divided according to the outer diameter are referred to as diameter regions 51, 52, 53, and 54, respectively. The diameter regions 51 to 54 are arranged in order from the distal end side to the proximal end side along the extending direction.

  Hereinafter, the length in the extending direction of each of the radial regions 51, 52, 53, and 54 is denoted as L51 (see FIG. 2), L52 (see FIG. 2), L53 (see FIG. 1), and L54 (see FIG. 1). In this case, the lengths are approximately 0.6 mm (L51), approximately 90 mm (L52), approximately 30 mm (L53), and approximately 1495 mm (L54).

  The outer diameters of the diameter regions 51, 52, 53, and 54 are denoted as R51 (see FIG. 5), R52 (see FIG. 6), R53 (see FIG. 7), and R54 (see FIGS. 8 and 9), respectively. In this case, the outer diameters are approximately 0.58 mm (R51), approximately 0.67 mm (R52), approximately 0.67 mm to approximately 0.8 mm (R53), and approximately 0.8 mm (R54). The outer diameters R51, R52, and R54 in the diameter regions 51, 52, and 54 are substantially the same over the extending direction in each region. On the other hand, the outer diameter R53 in the diameter region 53 is approximately 0.67 mm at the distal end of the diameter region 53 and is approximately 0.8 mm at the proximal end of the diameter region 53. The outer diameter R53 of the diameter region 53 gradually increases from the distal end side toward the proximal end side.

  As described above, the outer diameter of the tubular member 5 increases stepwise from the most distal-side diameter region 51 toward the most proximal-side diameter region 54. The coiled proximal end 3B (see FIG. 3) of the coiled portion 3 of the reinforcing member 2, the meshed distal end 4P (see FIG. 3) of the meshed portion 4, and the fastening portion 8 (see FIG. 3) have a radial region in the extending direction. 54.

  As shown in FIG. 1, the tubular member 5 can be divided into seven regions according to the hardness. Hereinafter, the seven regions classified according to the hardness are referred to as hardness regions 501, 502, 503, 504, 505, 506, and 507, respectively. The hardness regions 501 to 507 are arranged in order from the distal end side to the proximal end side along the extending direction.

  Hereinafter, the length in the extending direction of each of the hardness regions 501, 502, 503, 504, 505, 506, and 507 is expressed as L501, L502, L503, L504, L505, L506, and L507. In this case, the lengths are approximately 5 mm (L501), approximately 5 mm (L502), approximately 50 mm (L503), approximately 70 mm (L504), approximately 110 mm (L505), approximately 30 mm (L506), and approximately 1345 mm (L507). It is. The hardness of each of the hardness regions 501, 502, 503, 504, 505, 506, 507 is approximately 30D (hardness region 501), approximately 43D (hardness region 502), approximately 48D (hardness region 503), They are approximately 52D (hardness region 504), approximately 63D (hardness region 505), approximately 68D (hardness region 506), and approximately 74D (hardness region 507). The hardness of each of the hardness regions 501 to 507 is substantially the same in the extending direction in each region.

  As described above, the hardness of the tubular member 5 increases stepwise from the most distal end hardness region 501 toward the most proximal end region 507. The coiled proximal end 3B (see FIG. 3) of the coiled portion 3 of the reinforcing member 2, the meshed distal end 4P (see FIG. 3) of the meshed portion 4, and the fastening portion 8 (see FIG. 3) are hard in the extending direction. It is included in the area 507.

  As shown in FIG. 2, the boundary region between the hardness regions 501 and 502 having different hardnesses in the stretching direction and the hardness regions 502 and 503 are arranged in the diameter region 52 whose outer diameter is substantially the same in the stretching direction. The boundary part of is included. As shown in FIG. 1, the diameter region 52 includes a boundary portion between the hardness regions 503 and 504. In addition, in the diameter region 54 whose outer diameter is substantially the same in the stretching direction, the boundary portion of the hardness regions 504 and 505 having different hardness in the stretching direction, the boundary portion of the hardness regions 505 and 506, and the hard region The boundary portion of the vertical regions 506 and 507 is included.

  In the tubular member 5, different hardnesses are realized as described above by adjusting the composition of the materials of the hardness regions 501 to 507. In addition, the hardness of the catheter 1 itself affects the hardness of the reinforcing member 2 in addition to the hardness of the tubular member 5. However, since the hardness of the tubular member 5 is dominant with respect to the hardness of the reinforcing member 2, the height of the catheter 1 is substantially the same as the hardness of the tubular member 5.

<Usage of catheter 1>
An example of how to use the catheter 1 will be described. First, the user shapes (shapes) the distal end of the catheter 1 as necessary. The user is a doctor or the like. Next, the lumens 3A, 4A, and 5A of the catheter 1 are passed through the guide wire that has been previously inserted into the blood vessel. The user applies force to the proximal end side of the catheter 1 and pushes the catheter 1 into the blood vessel in order from the distal end side. Note that the user moves the catheter 1 forward while confirming the position and movement of the fastening portions 6 to 8 of the catheter 1 under fluoroscopy. Further, the user rotates the catheter 1 as necessary, and points the distal end of the catheter 1 in a desired direction. In this way, the user causes the distal end of the catheter 1 to reach the target site in the blood vessel.

  Thereafter, the user removes the guide wire from the catheter 1. In this state, the user injects a contrast medium from the connector 9 or inserts an embolic material as necessary.

<Main functions and effects of this embodiment>
In the catheter 1, the mesh portion 4 provided on the proximal end side in the extending direction of the reinforcing member 2 is excellent in pushability and torque transmission. For this reason, the mesh part 4 can transmit the force of the extending | stretching direction applied to the base end side appropriately to the front end side. Therefore, the user can appropriately advance the catheter 1 to the target site in the blood vessel. In addition, the mesh portion 4 can appropriately transmit the rotational force applied to the proximal end side to the distal end side. Therefore, even when the user rotates the proximal end side to direct the distal end of the catheter 1 in a desired direction, the distal end of the catheter 1 can be appropriately rotated.

  On the other hand, the coiled portion 3 provided on the distal end side in the extending direction of the reinforcing member 2 is excellent in followability and kink resistance. Therefore, the coiled portion 3 can smoothly advance the catheter 1 along the blood vessel when the catheter 1 moves forward in the blood vessel where the catheter 1 is bent to the target site. In addition, the coiled portion 3 can prevent the lumen from being crushed by being bent at a bent portion near the target site of the blood vessel. In particular, the catheter 1 is often used by inserting a distal end portion into a portion of a blood vessel where the degree of bending is large. In such a case, the coil-shaped part 3 arrange | positioned at the front-end | tip part of the catheter 1 functions effectively by the outstanding followable | trackability and kink resistance.

  Further, in the reinforcing member 2, the coiled portion 3 and the mesh portion 4 are joined by the fastening portion 8. For this reason, the reinforcing member 2 can have both the pushability and torque transmission performance of the mesh portion 4 and the followability and kink resistance of the coiled portion 3. Therefore, the catheter 1 provided with the reinforcing member 2 can realize excellent characteristics in pushability, torque transmission property, followability, and kink resistance.

  The fastening portion 8 has a cylindrical shape and covers the vicinity of the coiled base end 3B of the coiled portion 3 and the vicinity of the meshed tip 4P of the meshed portion 4 from the outside. The fastening portion 8 joins the coiled portion 3 and the mesh portion 4 by being caulked by applying pressure from the outside to the inside of the catheter 1. For this reason, compared with the case where the coiled base end 3B of the coiled part 3 and the meshed distal end 4P of the meshed part 4 are directly joined with an adhesive or the like, the fastening part 8 is connected to the coiled part 3 and the meshed part 4. Can be properly joined. Moreover, the fastening part 8 can be used as an X-ray opaque marker by using the material of the fastening part 8 as a radiopaque member. Therefore, the user can move the catheter 1 forward in the blood vessel while confirming the joint portion between the coiled portion 3 and the mesh portion 4 with the joint portion under fluoroscopy.

  The catheter 1 is often used in a state where the distal end portion is inserted into a blood vessel having a large degree of bending. On the other hand, the coil pitch of the coil distal end region 31 of the coiled portion 3 gradually increases from approximately 0.1 mm from the proximal end side toward the coiled distal end 3P. As a result, the coil tip region 31 of the coiled portion 3 can be made as soft as the coiled tip 3P. That is, the followability at the distal end of the catheter 1 is particularly excellent. For this reason, the catheter 1 can insert the distal end portion even in a blood vessel having a large degree of bending.

  In the catheter 1, the curvature when bent according to the application of an external force changes according to the hardness. For this reason, the curvature also changes abruptly at a portion where the hardness changes abruptly in the stretching direction. In addition, in the catheter 1, since the one where the change of the curvature when bent is smaller is preferable, the one where the change of the hardness of the extension direction in the catheter 1 is smaller is preferable. Here, usually, the hardness of the coiled portion 3 is often smaller than the hardness of the mesh portion 4. On the other hand, the coil pitch of the coil proximal end region 32 gradually decreases from about 0.1 mm toward the coiled proximal end 3B from the distal end side. As a result, the coil base end region 32 of the coiled portion 3 can be made as hard as the coil base end 3B. For this reason, the reinforcement member 2 can make small the change of the hardness of the extending | stretching direction in the boundary part of the coil-shaped part 3 and the mesh-shaped part 4. FIG. Accordingly, the catheter 1 can have a substantially constant curvature when bent.

  In order for the catheter 1 to move smoothly in the blood vessel, the outer diameter of the catheter 1 is preferably uniform. Further, in the catheter 1, the distal end portion, which is often inserted into a bent blood vessel, is preferably small in hardness, and the proximal end portion to which a force is applied directly when the catheter is pushed into the blood vessel from outside the body is preferred. The larger one is preferable.

  On the other hand, in the catheter 1, the outer diameters R52 and R54 in the diameter regions 52 and 54 of the tubular member 5 are substantially the same over the extending direction. Further, the diameter region 52 includes a boundary portion of the hardness regions 501 and 502, which have different hardnesses in the stretching direction, a boundary portion of the hardness regions 502 and 503, and a boundary portion of the hardness regions 503 and 504. Further, the diameter region 54 includes boundary portions of the hardness regions 504 and 505 having different hardnesses in the stretching direction, boundary portions of the hardness regions 505 and 506, and boundary portions of the hardness regions 506 and 507. That is, a portion having a different hardness is included in the region of the tubular member 5 where the outer diameter is substantially the same. For this reason, the catheter 1 can reduce the hardness of the distal end side in a stepwise manner and increase the proximal side hardness in a stepwise manner while keeping the outer diameter substantially the same. Therefore, the catheter 1 can realize characteristics excellent in followability at the distal end portion and pushability at the proximal end portion.

  The coiled base end 3B of the coiled portion 3, the meshed tip 4P of the meshed portion 4, and the fastening portion 8 are included in the hardness region 507 in the extending direction. In addition, the hardness of the hardness area | region 507 is substantially the same over the extending | stretching direction. That is, the fastening portion 8 where the coil-like portion 3 and the mesh-like portion 4 are joined in the reinforcing member 2 is included in the hardness region 507 having substantially the same hardness in the tubular member 5. In this case, the difference in hardness between the coil-like portion 3 and the mesh-like portion 4 in the reinforcing member 2 can be alleviated by the tubular member 5. Therefore, since the catheter 1 can reduce the change in the hardness in the extending direction at the joint portion between the coiled portion 3 and the mesh portion 4, the curvature when the catheter 1 is bent can be made substantially constant.

<Modification>
The present invention is not limited to the above embodiment, and various modifications can be made. The present invention is not limited by the dimensions, ratios, materials, and the like of the components described above, and these can be changed as appropriate. In the above, the catheter 1 has a configuration including the reinforcing member 2 and the tubular member 5. On the other hand, the catheter 1 may have a configuration including only the reinforcing member 2. The reinforcing member 2 may not have the fastening portions 6 and 7.

  The cross-sectional shape of the wire constituting the coil-like part 3 and the net-like part 4 is not limited to a circle. For example, the wire may be flat. The strand may be formed by weaving fine fibers having a circular cross-sectional shape. The coil-shaped part 3 may have a plurality of coils concentrically stacked around an axis extending along the extending direction. Further, the plurality of coils may be wound in the same direction, or may be wound in different directions. The woven structure of the mesh portion 4 is not limited to the twill weave, and may be a plain weave. Moreover, the mesh part 4 may be formed of a turtle shell metal mesh. The coiled base end 3B of the coiled part 3 and the meshed tip 4P of the meshed part 4 may be slightly separated in the extending direction.

  A part of the coiled part 3 including the coiled base end 3B and a part of the meshed part 4 including the meshed tip 4P may overlap in the extending direction. In this case, the coiled base end 3B is located closer to the base end side in the extending direction than the net-like tip 4P. Further, in this case, a part of the coiled portion 3 including the coiled base end 3B may be arranged outside or a part of the meshed portion 4 including the meshed tip 4P. May be arranged. In this case, a part of the coiled part 3 including the coiled base end 3B and a part of the meshed part 4 including the mesh tip 4P may be knitted together. Furthermore, in this case, the coil-like part 3 and the mesh-like part 4 may be joined to each other by an adhesive or laser welding. In addition, when the part which mutually overlaps is joined by an adhesive agent etc., the fastening part 8 does not need to be provided.

  In the coiled portion 3 and the meshed portion 4, the coiled proximal end 3B and the meshed distal end 4P may contact each other. In this case, the coiled base end 3B and the mesh tip 4P are disposed at the same position in the extending direction. In this case, the coiled base end 3B of the coiled portion 3 and the meshed tip 4P of the meshed portion 4 may be joined by an adhesive or laser welding. When the coiled base end 3B and the mesh tip 4P are joined by an adhesive or the like, the fastening portion 8 may not be provided.

  The fastening portion 8 can be changed to a member having another shape capable of joining the coiled base end 3 </ b> B of the coiled portion 3 and the meshed tip 4 </ b> P of the meshed portion 4. For example, the fastening portion 8 may be formed with a plurality of slits extending along the extending direction, or may be formed with a plurality of holes. The fastening portion 8 may have a coil shape in which the wire is wound in a coil shape, or may have a tubular shape in which the wire is knitted in a net shape. The material of the fastening portion 8 is not limited to the radiopaque member, and may be another material (for example, SUS).

  The coil pitch in the coil distal end region 31 of the coiled portion 3 may gradually become smaller than approximately 0.1 mm from the proximal end side toward the coiled distal end 3P. The coil pitch of the coil proximal end region 32 may gradually become larger than approximately 0.1 mm from the distal end side toward the coiled proximal end 3B. The coil pitch of the coil-shaped part 3 may be substantially the same over the entire region in the extending direction. The coil-shaped portion 3 may have a coil central region between the coil tip region 31 and the coil base region 32 that has a coil pitch of approximately 0.1 mm that is substantially the same in the extending direction.

  The positions in the extending direction of the boundaries of the diameter regions 51 to 54 and the boundaries of the four adjacent regions of the hardness regions 501 to 507 may coincide. That is, in the tubular member 5 of the catheter 1, the region where the outer diameter is substantially the same and the region where the hardness is substantially the same may be arranged at the same position in the extending direction. The tubular member 5 may have different hardness on the distal end side and the proximal end side with respect to the boundary position between the coiled portion 3 and the mesh portion 4 of the reinforcing member 2.

  Each of the hardness regions 501 to 507 had substantially the same hardness in the stretching direction. On the other hand, at least one of the hardness regions 501 to 507 may have different hardness in the stretching direction. In this case, for example, the hardness in the specific hardness region may gradually change from the hardness of the hardness region adjacent to the distal end side to the hardness region adjacent to the proximal end side. Specifically, for example, the hardness region 504 gradually changes from the hardness (approximately 48D) of the hardness region 503 to the hardness of the hardness region 505 (approximately 63D) from the distal end side toward the proximal end side. Also good. Further, for example, the hardness regions 504, 505, and 506 gradually change from the hardness of the hardness region 503 (approximately 48D) to the hardness of the hardness region 507 (approximately 74D) from the distal end side toward the proximal end side. May be. Thus, the catheter 1 can moderately change the hardness by gradually changing the hardness in a specific hardness region. Therefore, a change in curvature when the catheter 1 is bent can be suppressed.

<Others>
The fastening portion 8 is an example of the “joining portion” in the present invention.

DESCRIPTION OF SYMBOLS 1: Catheter 2: Reinforcing member 3: Coiled part 3A, 4A, 5A: Lumen 3B: Coiled base end 3P: Coiled tip 4: Meshed part 4P: Meshed tip 5: Tubular members 6, 7, 8: Fastening Part 31: Coil distal end region 32: Coil proximal end region

Claims (11)

A reinforcing member that extends from the proximal end to the distal end along the extending direction and reinforces the catheter,
A tubular member in which a wire is wound in a coil shape, and a coil-shaped portion having a lumen extending from the distal end toward the proximal end along the extending direction;
A tubular member in which strands are knitted in a net shape, and a lumen includes a net-like portion extending from the proximal end to the distal end side along the extending direction;
The inner ends of the coiled portions communicated with each other by joining the coiled proximal end, which is the proximal end of the coiled portion, and the meshed tip, which is the distal end of the meshed portion. A reinforcing member characterized by the above.   The reinforcing member according to claim 1, further comprising a joint portion that joins the coiled base end and the mesh tip. The joint is
3. The reinforcing member according to claim 2, further comprising a fastening portion that covers the coiled base end and the meshed distal end from the outside in the radial direction of the lumen of each of the coiled portion and the meshed portion.   The reinforcing member according to claim 3, wherein the material of the fastening portion is a radiopaque member.   The reinforcing member according to any one of claims 1 to 4, wherein the coiled base end is positioned on the base end side in the extending direction with respect to the mesh tip.   The coil pitch of a coil distal end region including at least a coiled distal end that is an end on the distal end side of the coiled portion gradually increases from the proximal end side toward the coiled distal end. The reinforcing member according to any one of 5.   The coil pitch of a coil proximal end region including at least the coiled proximal end of the coil-shaped portion gradually decreases from the distal end side toward the coiled proximal end. Reinforcing member as described in 2. The reinforcing member according to any one of claims 1 to 7,
A catheter comprising a tubular member covering the reinforcing member. The tubular member has the same diameter region where the outer diameter is substantially the same over the extending direction,
The catheter according to claim 8, wherein the same-diameter region has a portion whose hardness is different in the extending direction. The tubular member has a hardness identical region where the hardness is substantially the same over the extending direction,
The catheter according to claim 8 or 9, wherein a portion where the coiled proximal end and the mesh distal end are joined is included in the same hardness region. The tubular member is a plurality of regions extending in the extending direction, and includes a first region, a second region, and a third region sandwiched between the first region and the second region,
The hardness of the first region is the first hardness;
The hardness of the second region is a second hardness greater than the first hardness;
The hardness of the third region changes from the first hardness to the second hardness from the first region side toward the second region side. The catheter described.

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